1. Field of the Invention
In at least one aspect, the invention relates in general to articles joined together by spray forming and, more particularly, to articles produced by spray joining together one or more smaller spray formed articles.
2. Background Art
It is well known to make spray formed articles such as relatively small spray formed tools and dies. In a typical spray forming process, a metallic material, such as steel, is sprayed onto a pattern, typically made of ceramic, and allowed to cool to form a desired article. These articles typically have length and width dimensions ranging between about 1 millimeter by 1 millimeter to about 1 meter by 1 meter.
Because of various spatial and processing limitations, mainly dealing with maintaining the spray forming temperature at a certain level, it has been somewhat impractical to produce spray formed articles larger than about one meter by one meter. As such, there are many types of steel articles that because of their shape or size are not able to be formed by conventional spray forming processes. For instance, one-piece molding shells and stamping tools for large parts, such as automobile hoods, have not been successfully formed using conventional spray forming techniques because of the inherent limitations in current spray forming techniques.
Additionally, there are instances where it is desirable to join a spray formed particle, of a specific type of metal, with a second article of a different type of metal. For instance, there are several instances where it is desirable to have a screw, or other fastening rod, secured to a spray formed article. One particular example is with a lay-up tool or one-sided tool which requires a back support structure attached to the spray formed face. Presently, acceptable bonds between articles of dissimilar materials are not able to be obtained via welding or other conventional metal joining techniques.
Accordingly, it would be desirable to provide a process for manufacturing articles of the shapes and/or sizes and/or constitutions discussed above via conventional spray forming processes.
In at least one embodiment, the present invention takes the form of a method of spray forming together at least two or more articles. The method comprises providing a first spray formed article and locating a second article adjacent the first article. The method further comprises spraying metallic particles onto the articles and allowing the sprayed metal particles to form a metal deposit connecting the first article with the second article.